The judge in the Pirate Bay trial has been cleared of any accusations of bias, a Swedish court of appeal ruled today.

In April it was revealed that Thomas Norström was a member of the same pro-copyright groups as several of the main entertainment industry reps in the case.

At the time the judge meted out sentences and fines to the four co-founders of the notorious BitTorrent tracker site.

The plaintiffs' lawyers demanded a retrial after it emerged that Norström was signed up to the Swedish Copyright Association (Svenska föreningen för upphovsrätt), which also counts Henrik Pontén, Peter Danowsky and Monique Wadsted as members.

All three represented the music and film industry in the case.

"The court has come to the conclusion that none of these circumstances, neither alone nor together, means there is doubt on whether the judge was objective," the court said in a statement, reports Reuters.

The Pirate Bay four, who were convicted of being accessories to breaching copyright laws, fired off an official appeal against the $3.6m fine and one-year jail terms they were handed by a Swedish court in Mid-April.